Alpha radiation is heavy, slow moving and doesn't penetrate very far into materials.
It is released my fairly heavy nuclei e.g. uranium.
Alpha radiation has 2 protons and 2 neutrons which gives it a mass of 4. It has a charge of 2.
Alpha radiation always changes the nucelus of the element it's decaying because it loses protons.
Beta radiation is light, fast and can moderately penetrate into materials.
It is released from nuclei with too many neutrons.